The candidate's long term goals are to become a fully independent investigator and join the faculty of an academic medical school. The short term goals are to gain superior skills and background understanding of molecular biology and receptor biology. The career development plan provides for intense mentoring, didactic instruction and close supervision by an advisory committee. The environment at this institution provides a number of individuals with superior skills in immunology, virology, molecular biology and chemokine biology. The broad, long term goals of this project are to understand the role of chemokines in viral infection and to develop novel compounds to inhibit the inflammatory response. The theoretical model to be used is that virus infection of cells results in a release of chemokines that attempt to recruit inflammatory cells. The molluscum contagiosum virus (MCV) is able to then make a protein that specifically blocks the effects of these released chemokines, thus preventing an inflammatory response and elimination of the virus itself. The specific hypotheses to be tested are: 1) the viral protein is made very early in the viral life cycle in order to effectively block the innate immune response. 2) The viral protein is able to block the action of multiple chemokines and block the chemotaxis of multiple inflammatory cell types. 3) The viral chemokine accomplishes it's effects by binding to but not activating chemokine receptors. 4) Structural features of the viral protein at the amino terminus and an internal site known as the heparin binding site are important for the function of this protein. The specific aims of this research are: 1) To characterize the time course of production after infection of the viral chemokine inhibitor protein, MC148R, by infecting keratinocytes with MCV and testing for mRNA production and protein production. 2) To identify the ability of MC148R to block chemotaxis induced by a panel of chemokines, and to identify which subsets of inflammatory cells are blocked by MC148R. 3) To characterize the ability of MC148R to bind to chemokine receptors and induce an intracellular signal. Binding will be assayed by radioactively labeling MC148R and demonstrating radioactivity on cells carrying cloned chemokine receptors. Intracellular signaling will be assayed using a calcium flux assay in cells with cloned chemokine receptors. 4) To determine the regions of MC148R that are important for blocking chemotaxis by constructing mutant proteins at both the amino terminus and the internal heparin binding site.